GatorBoard is much stiffer and has a smoother, resin impregnated outer paper layer compared to Foamcore. There is one difference that is noteworthy. Self adhesive materials adhere much better to Foamcore as the outer paper is more matte than the paper on GatorBoard. The outer paper of GatorBoard is resin impregnated, which may be the reason for the different adhesion properties. One up side of GatorBoard's lower adhesion is that it can be used as a sled for lamination and the excess laminates is easily removed from the board so it can be used many times for this purpose. BTW, Foamcore and GatorBoard are available in the same thicknesses.